THRESHOLD CHARACTERISTICS AND INTENSITY FLUCTUATIONS OF LASERS WITH EXCESS QUANTUM-NOISE

We discuss the threshold characteristics and intensity noise of a lase r with excess quantum noise as occurs, e.g., in an unstable-cavity las er. We give a theoretical description of the intensity aspects of exce ss noise based on laser rate equations, including bad-cavity effects. Experimentally, we have measured spectra of intensity noise and phase noise of small HeXe gas lasers. We operate the laser on either a stabl e or an unstable cavity, in order to change from a situation of no exc ess noise to large excess noise. By comparing the measured spectra wit h the theory, we deduce the excess-noise factor K and the spontaneous- emission factor beta. [S1050-2947(98)01401-2].